Six men and one woman have been arrested after raids on seven addresses in London and Luton as part of a probe into allegations that vulnerable and elderly victims are 'cold-called' by someone impersonating a police officer and scammed out of money.

The men, all in their 20s and 30s, were arrested on suspicion of conspiracy to commit fraud and money laundering and a 32-year-old woman was arrested on suspicion of money laundering.

A 46-year-old woman was also arrested during a property search in north London on suspicion of a separate offence under the Child Abduction Act in relation to a young girl travelling to Turkey whose whereabouts remain unknown.

She has been bailed until June alongside two women, aged 20 and 21, who were previously arrested in relation to this inquiry.

Officers are investigating a large-scale fraud linked to UK extremists travelling to Syria.

The arrests today form part of an ongoing fraud investigation, whereby unsuspecting vulnerable and elderly victims are 'cold called' on their home phone by a suspect impersonating a police officer.

Members of the public are strongly advised, if you receive a call like this about your bank account from someone claiming to be a police officer, hang up the phone, wait at least five minutes to make sure the phone line has cleared, or use another phone line, before ringing the phone number on your bank card.